B OBBY JINDAL 

GOVERNOR 

Mr. Ron Curry 

~tate of JLoutstana 

DEPARTMENT OF ENVIRONMENTAL QUALI1Y 

ENVTRO~NTALSERVICES 

Regional Administrator (6RA) 

U.S. Environmental Protection Agency, Region 6 

1445 Ross Avenue, Suite 1200 

Dallas, Texas 75202-2733 

RE: Authorized Emissions for Purposes of LAC 33:III.504 and 509 

Docket No. EPA-R06-0AR-2006-0131 

Dear Mr. Curry: 

PEGGY M . HATCH 

SECRETARY 

On December 31 , 2002, the Environmental Protection Agency (EPA) promulgated revisions to 

the federal Prevention of Significant Deterioration (PSD) and Nonattainment New Source 

Review (NNSR) programs. 

1 The final rule required states to "adopt and submit revisions to their 

part 51 permittin:P programs implementing these minimum program elements no later than 

January 2, 2006." On December 20, 2005, the Louisiana Department of Environmental Quality 

(LDEQ) submitted the necessary amendments to LAC 33:III.504 ~SR) and LAC 33:III.509 

(PSD) as a revision to Louisiana's State Implementation Plan (SIP). 

LAC 33:III.504 and 509 essentially mirror their federal counterparts under 40 CFR 51.165 and 

166; however, the state provisions utilize the term "authorized" in the context of emissions 

associated with start-ups, shutdowns, and malfunctions, a term not found in the federal rules. 

Affected citations include: 

• LAC 33:III.504.J.3.b 

• LAC 33:III.504.K.Baseline Actual Emissions.a.i 

• LAC 33:III.504.K.Baseline Actual Emissions.b.i 

• LAC 33 :III.504.K.Projected Actual Emissions.b 

• LAC 33:III.509.B.Baseline Actual Emissions.a.i 

• LAC 33:III.509.B.Baseline Actual Emissions.b.i 

• LAC 33 :III.509.B.Projected Actual Emissions.b 

• LAC 33:III.509.AA.3.b 

LDEQ's SIP submission included the requisite "demonstration of equivalency," which IS 

repeated in relevant part below. 

The department believes use of the term "authorized" is consistent with federal 

language requiring the average rate, when calculating baseline actual emissions, to be 

adjusted downward to exclude any non-compliant emissions that occurred while the 

source was operating above any emission limitation that was legally enforceable 

during the consecutive 24-month period. Also, when determining projected actual 

emissions, a source should not assume this figure will be greater than its potential to 

emit (i.e., include emissions not "authorized" by its permit).4 

I 67 FR 80186 2 67 FR 80240 3 EDMS Doc ID 6431380 4 /d. (p. 5 of 403) 

Post Office Box 4313 • Baton Rouge, Louisiana 70821-4313 • Phone 225-219-3181 • Fax 225-219-3309 

www.deq.louisiana.gov 
Mr. Ron Curry 

Page 2 

During its review of Louisiana's SIP revision, Region 6 has requested that LDEQ clarify certain 

matters as they relate to the aforementioned citations. In response, LDEQ offers the following 

information: 

• 

• 

• 

• 

• 

• 

• 

• 

In the context of LAC 33:III.504 and 509, the term "authorized emissions" refers to 

emissions authorized through a valid air permit issued pursuant to LAC 33:III.Chapter 5. 

LDEQ's definitions of "baseline actual emissions" require such emissions to be based on 

"the average rate, in tons per year, at which the unit actually emitted the pollutant during 

any consecutive 24-month period." 

When assessing baseline actual emissions from a permitted emissions unit, the average rate 

must be "adjusted downward to exclude any non-compliant emissions that occurred while 

the source was operating above an emission limitation that was legally enforceable during 

the consecutive 24-month period." All non-compliant emissions, including those 

associated with malfunctions, must be subtracted from the "the average rate." 

A variance is not a permit, but rather a finite "waiver issued under the authority of the 

Department of Environmental Quality upon application to allow emissions greater than 

those allowable under the regulations and/or a license to do some act contrary to [the] 

regulations." 5 Variances are issued prospectively for periods of time no lon-#er than one 

year and cannot be used to authorize emissions which have already occurred. 6

• 

Baseline actual emissions cannot exceed permitted limits, even if additional emissions have 

been approved by means of a variance or Declaration of Emergency and Administrative 

Order (hereafter Emergency Order).

8 

Emissions from an unpermitted emissions unit temporarily authorized to operate in place of 

a permitted emissions unit by means of a variance or Emergency Order cannot be counted 

as baseline actual emissions. · 

Should LDEQ calculate baseline actual emissions using its definition in LAC 33:III.504.K 

or 509.B, the result would be no different than if the federal definition at 40 CFR 

51.165(a)(l)(xxxv) or 51.166(b)(47) was utilized. 

If a physical change or change in the method of operation results in a significant emissions 

increase and a significant net emissions increase, the project is subject to applicable New 

Source Review (NSR) requirements. Construction of a project that causes a significant 

emissions increase and a significant net emissions increase without the appropriate NSR 

permit is a violation of the Act and subject to enforcement action, even if preconstruction 

projections did not indicate the project would trigger NSR or the emissions increase 

associated with the rroject would have been less than "significant" due to a variance or 

Emergency Order.9

•

1 

5 LAC 33 :III.III.A 6 R.S. 30:2056(C) 7 Louisiana Guidance for Air Permitting Actions, rev. 5 (Section 2.2.3) 

(http://www. deq .louis ian a. gov /portal/DIVISIONS/ Air PerrnitsEngi neeringandP I ann ing.aspx) 8 Declarations of emergencies are addressed by R.S. 30:2033. 9 "Technical Support Document for the Prevention of Significant Deterioration and Nonattainment New Source 

Review Regulations," U.S. EPA, November 2002 (p. I-4-8) 10 LAC 33 :III.504.D; LAC 33 :III.509.A.3 
Mr. Ron Curry 

Page 3 

In sum, a variance is not a permit, but rather a waiver issued prospectively by LDEQ to allow 

emissions from an emissions unit to temporarily exceed permitted limitations or to authorize the 

use of a temporary emissions unit not addressed by an air permit. 11 A variance cannot function to 

increase baseline actual emissions over permitted limits, nor can emissions from a temporary 

emissions unit authorized via a variance count towards baseline actual emissions. In evaluating a 

prospective project for NSR applicability, if a permittee chooses a 24-month period during which 

a variance was in place for one or more affected emissions units, the permittee must "adjust 

downward" (i.e., discount) any actual emissions not expressly authorized by its air permit, even 

if such emissions were approved through variance procedures. Alternatively, the permittee may 

select another 24-month period. 

LDEQ's use of the term "authorized" does not expand the meaning of "baseline actual 

emissions" or "projected actual emissions" in a manner to render the submitted revisions to LAC 

33:III.504 and 509 less stringent than their corresponding federal provisions. Accordingly, a 

permittee cannot circumvent what would otherwise be applicable NSR requirements or 

improperly establish a plantwide applicability limit (PAL) by means of an LDEQ-issued variance 

or Emergency Order. 

Finally, LDEQ notes that the term "authorized" is used differently in the context of LAC 

33:III.919 (Emissions Inventory) and the reporting of actual emissions to LDEQ's Emissions 

Reporting and Inventory Center (ERIC). LDEQ will amend its "Louisiana Guidance for Air 

Permitting Actions" to clarify that, for purposes of baseline actual emissions and projected actual 

emissions, "authorized" emissions cannot exceed the limitations imposed by an air permit issued 

pursuant to LAC 33:III.Chapter 5. 

If you have any questions about this matter, please contact Bryan D. Johnston of the Air Permits 

Division at (225) 219-3450. 

Sincerely, 

Date 

TBT:BDJ 

I I Variances may also address other circumstances.